Below is a round-up of the birth announcements from British newspapers. Sources include a national paper (The Telegraph, The Times) and a broad range of local newspapers from across England, Wales, Scotland and Northern Ireland.
Sibling names are in brackets. No official surnames are included; any name ending in a surname is actually a middle name.
Boys:
Albert George
Alexander George Theodore (Charlotte)
Alexander Orf (William)
Alexander William Edward
Angus Jude
Austin Charles (Camilla Caroline Sara)
Bertie Philip Robert Chandos
Blaise Atlas Jude (Zadie Grace Valentine & Sasha Raphael Phoenix)
Caspar Tristram Dig
Charles James
Charles Patrick (Archie Peter & Edward Blake)
Christopher Michael Dean
Cosmo Alexander Harry
Edward Felix Charles
Ezra Peter
Felix John (Topsy Malory)
Finlay Thomas (Molly & Ted)
Frederick Desmond Thomas
Gabriel Henry Adrian
Hamish Robert Marmaduke
Hector Robin
Henry "Harry" Augustus Hugh
Henry Christopher
Ivo Rupert Marlow (Wilf & Jocelyn)
Jack Francis Noel (Frederick Clive Mytton)
Jacob Edward James
Lachlan Hunter
Laurence John
Leo Alexander
Lorcan “Laurie” Marlow (Zelda Emily & Orlando "Ozzie" Marlow)
Lucas John (Charlotte Elizabeth)
Max Finn
Max Peter
Max Robert David (Jack & Emma Hazel)
Miles Leo
Montgomery James (Araminta Elspeth)
Oran Thomas
Orlando Valentine Edward (Percy)
Oscar James
Phoenix Rose
Raf Isaac
Ranulph Benjamin Piran
Reggie Alasdair
Rollo Arthur Frederick (Sebastian Felix Clough)
Ruairidh Alexander Scott
Theodore "Teddy" George Eugene
Timothy Andrew David
Zachary George Colin
Girls:
Annabel Charlotte
Annabel Jacqueline Dorothy
Artemis Jane
Astrid Phoebe
Aurora Sophia de Ceuleneer
Beatrice Elizabeth Margot
Bonnie Meara Grace (George Geoffrey Rigden)
Briony Mary
Cecilia Lucy Marie
Charlotte Roberta Mary (Elizabeth)
Clementine Eliza Rose (Maximilian Arthur Hugh)
Clementine Ottilie (Theodore Edward)
Constance Wingfield "Connie"
Cosima “Coco” Amelia (Leo & Arthur)
Cressida Mary
Daphne Jane Anastasia (Frankie)
Elizaveta Maria
Elodie Florence (Samuel George Ogilvie & Thomas William)
Ethel Cordelia Ruth
Florence Clementine Lily (Isabella Daisy Beatrix)
Harriet Rose Olivia
Henrietta Frances Marina
Isabella Carolyn
Isobel Francis
Lily Eliza Rose (George Exton & Edward "Teddy" Christopher Exton)
Lilyrose Irene Regine (Astrid Henriette Elizabeth)
Lucy Audrey Eve (Alice)
Ludovica Emma
Lulu Mable (Arthur Peter)
Mabel Beatrice
Mabel Mary Clancy (Oscar)
Matilda Violet Lucinda
Mia Elora (Poppy)
Molly Alice Isolde (Freddie & Kit)
Molly Margit (Sophie Gill Lily)
Olivia Elizabeth
Órla Alexandra Violet
Ottilie Sarah
Penelope May (Sebastian)
Poppy Lucinda
Poppy Olivia (Elliot)
Rosanna Violet
Ruby Clementine
Serena Mary (Lara)
Siena Domino (Sebastian)
Tamsin Mary (Ralph Christopher)
Tiggy Jane Joanna (Isla Olivia Rosemary & Artie Aubrey)
Viola Eve
Twins:
Percy Dean & Alfred Ralph (Bluebell Rose) - Mum is Lady Melissa Percy, daughter of the Duke of Northumberland
I cross-reference older BAs to find the full names of the siblings, however often they are missing (especially the eldest siblings, or for half-siblings) which explains why you will sometimes see something like: George Henry (Lucy, Emma & Jack Arthur). "Lucy" and "Emma" may well have middle names as well; I simply cannot find them online.